1940
- June 14 – In the Kaleva shootdown, an Aero Junkers Ju 52/3mge flying from Tallinn, Estonia to Helsinki, Finland is shot down by two Soviet bombers over the Gulf of Finland during peacetime; all nine aboard die.
- August 31 – The Lovettsville air disaster: Pennsylvania Central Airlines Trip 19, a Douglas DC-3A, crashes at Lovettsville, Virginia, killing all 25 aboard in the worst US airplane accident to that date, beginning the era of formal investigations under the Civil Aeronautics Board.
Read more about this topic: List Of Accidents And Incidents Involving Commercial Aircraft